1. Field of the Disclosure
The present disclosure is related to apparatus and methods for estimating inclination and orientation of a tool in a wellbore.
2. Description of the Related Art
Wellbores are drilled in earth's formations for the production of hydrocarbons (oil and gas). A large number of wells are deviated wells or horizontal wells. A typical profile for such wells may include a vertical section, a deviated or inclined section and a horizontal or substantially horizontal section. The drilling of such wellbores is accomplished by a drill string that includes a drilling assembly (also referred to as a bottomhole assembly or BHA) that includes a drill bit attached to its bottom end. The drill bit is rotated by rotating the drill string from the surface and or by rotating the drill bit with a drilling motor (also referred to as a “mud motor”) in the drilling assembly. Measurements made by multi-axis accelerometers and magnetometers in the drilling assembly are used to determine the inclination and orientation (azimuthal direction) of the drilling assembly in the formation relative to a reference, such as geographical north. The drilling assembly typically includes one or more steering devices for maintaining the drilling assembly along the desired well path or well profile, based on the determined inclination and orientation of the drilling assembly.
The disclosure herein provides an apparatus and method of determining inclination and orientation of a tool, such as the drilling assembly, using pressure measurements made downhole.